Overall spending increase — Online sales were up 33% over 2010, 29.3% up over Black Friday 2011, and AOV (avergage order value) also went up from $193.24 to $198.26

Conversion rate — Overall conversion rate went up from 5.6% in 2010 to 5.71%, mobile seeing the best improvement (from 2.24% to 2.99%)

Mobile sales growth — Nearly 11% of people used a mobile device to visit e-tailers’ websites (up from some 4% last year), resulting in a nearly threefold growth in mobile sales (6.6% in 2011 vs 2.3% in 2010)

Social media part — While “discussions leading up to Cyber Monday increased in volume by 115% compared to 2010”, resuling in 0.93% of site traffic, only 0.56% of Cyber Monday shoppers were referred directly from social networks.

To see what people have been buying (good data both for affiliates, and for merchants to review), especially in electronics — a niche that registered the highest growth – 26% over 2010 — see these lists by Larry Magid.

Make sure you also download IBM’s full 10-page Cyber Monday Report 2011 here [PDF file], which among other things also contains detailed information and 2011-vs-2010 comparisons of sales data in such categories as Apparel (one of the best in one-page bounce rates – 25.5%), Department Stores (champion in average session length – 8:18), Health and Beauty (best in conversion – 5.4%), and Home Goods (best 2011-over-2010 improvement – 68.4%, and largest AOV – $290.11).

Another valid point was raised by Betty Hakes, who wonders what exactly drove the mobile shopping. There are mobile social apps, and emails, and other cross-channel involvements that couldn’t be painted one color, but are closely intertwined (say, social + mobile, or email + mobile, as in her examples).